class BankAccount:
    def __init__(self, account_number, balance=0):
        self.account_number = account_number
        self.balance = balance

    def deposit(self, amount):
        if amount > 0:
            self.balance += amount
            return True
        else:
            return False

    def withdraw(self, amount):
        if amount > 0 and self.balance >= amount:
            self.balance -= amount
            return True
        else:
            return False

    def get_balance(self):
        return self.balance

# 创建一个银行账户实例
account = BankAccount("123456789", 1000)

# 存款操作
if account.deposit(500):
    print("存款成功")
else:
    print("存款失败")

# 取款操作
if account.withdraw(200):
    print("取款成功")
else:
    print("取款失败")

# 查询余额
print("当前余额：", account.get_balance())
